Study On The Synthesis And Mechanism Of Organosilicon Composite Cationic Flocculant

At present,there are two drawbacks in the synthetic cation-organic-polymer flocculant:firstly,its separate processing efficiency is low;secondly,its high cationic degree leads to high cost.Therefore,it is necessary to study on the high-efficiency cationic polymeric flocculant and reduce its cost.So a kind of silicon-contained flocculant with a web-like molecular configuration was designed and synthesized.Its Structural characterization and performance evaluation were carried out,and the mechanism of the flocculant was studied.Web-like cationic flocculant was synthesized by aqueous solution polymerization.The effects of different factors on the polymerization were investigated.The results showed that the flocculant with the intrinsic viscosity 1776 mL/g,the cationic degree 12.7%can be synthetized when the monomer concentration was 20wt%,n(AM):n(DMC)=8.5:1.5,the reaction temperature was 45 ?,the initiator V50 was 1.5wt%o of monomer concentration,the sodium silicate was 1.5wt%of monomer concentration,pH was 6,the urea ratio was 1.5%.The molecular structure of the flocculant was confirmed by IR and NMR.When the self-made flocculant was applied for the treatment of clay sewage with SS concentration of 1000mg/L,the result shows that the treatment capacity with 8mg/L flocculant dosage is optimal.Comparing this cationic flocculant with common one which has equivalent molecular weight and cationic degree,it is found that the treatment efficiency of silicon-contained flocculant is higher.After processing,the supernatant of the raw water is clearer and the flocs are more compact.The self-made flocculant were applied for comparative experiment of fracturing flow-back fluid in oil field,it shows that compared with common cationic flocculant which has higher molecular weight and higher cationic degree,their CODCr removal capacity is comparable.When the self-made flocculant mixed with inorganic coagulant,the situation can be improved greatly.In experiment,it is found that the compressive capacity of the inorganic coagulant is limited,and the mechanism is not the same when concentration of the inorganic coagulant is different.The mechanism of the flocculant was studied by scanning electron microscope(SEM)and Zeta potential analyzer.The result shows that besides adsorption bridging mechanism,the flocculant also relies on multiple point adsorption and envelope mechanism to make particles or colloidal destabilized.The web-like cationic flocculant has the similar treatment efficiency of common flocculant under the condition of low cationic degree.It can reduce production costs of this tape of flocculant.Some reasonable suggestions of the flocculant research are put forward in hopes of playing a beneficial guiding role to the cationic flocculant research and application.